Del Potro, who led Argentina to its first Davis Cup championship last season, skipped the 2017 Australian Open in order to rest and recovery.

“I think I will have a good chance to go up in the rankings next season," del Potro told the media in Stockholm. "Because I didn’t play the Australian Open tournament and I quit the most tournaments on clay this year. I only played Wimbledon on grass.

"Next year, could be a good chance to keep improving and I just want to finish the year in good shape and be ready for a good pre-season. I think I will start very early in the year to take advantage of that."

Four wrist surgeries, including three on his left wrist, limited the 2009 US Open champion to hitting slice backhands almost exclusively in the early stages of his comeback. Del Potro said he's now feeling more confident driving through his topspin backhand and has more options with the slice.

"I improved a lot my slices, my volleys and now I’m hitting harder my two-handed backhand, which is very important for playing this surface," del Potro said. "I think I’m in good form, even better than last year, now it’s time to play and see how I am doing."